Such a container as described in US patent publication 2012/0103465 has a cylindrical housing having one end formed with an intake opening connected to the source of liquid lubricant, typically a bearing connected to an automatic lubricant doser. In one embodiment a piston subdivides the container into a front compartment into which the intake opening opens and a back compartment that is open to the outside through the wide-open rear end of the container. The piston can thus be moved back as the compartment fills until it engages stops preventing further movement. In another embodiment the rear end of the container is covered with a cap having a vent hole and instead of a piston a bladder inside the container is compressed as the front compartment fills.
The problem with the piston system is that if the collecting container is filled with lubricant and lubricant continues to flow, the lubricant can escape out of the collecting container past the piston. This is in particular a problem when a piston has to be built so that it can be moved particularly easily, that is with the lowest pressure difference and thus with low seal pressing and the old lubricant due to thermal stress and pressure stress tends to bleed out, that is, to segregate oil portions.
The disadvantage of the system with the membrane is that, after being filled, the collecting container cannot be emptied again or can be emptied again only with effort.